1.  10. The standard molar enthalpy of formation of NH_{3}(g) is –45.9 kJ/mol. What is the enthalpy change if 9.51 g N_{2}(g) and 1.96 g H_{2}(g) react to produce NH_{3}(g)? 
A. 
B. 
C. 
D. 
E. 
2.  What is the correct equilibrium constant expression for the following reaction? CO_{2}(g) + 2H_{2}O(g) CH_{4}(g) + 2O_{2}(g) a. b. c. d. 
A. 
B. 
C. 
D. 
3.  14. Dinitrogen pentaoxide decomposes to nitrogen dioxide and oxygen according to the following balanced chemical equation and rate expression. 2N_{2}O_{5}(g) → 4NO_{2}(g) + O_{2}(g) rate = k[N_{2}O_{5}] What is the overall reaction order? 
A. 
B. 
C. 
D. 
E. 
4.  6. When 10.0 g KOH is dissolved in 100.0 g of water in a coffeecup calorimeter, the temperature rises from 25.18 ^{0}C to 47.53 ^{0}C. What is the enthalpy change per gram of KOH dissolved in the water? Assume that the solution has a specific heat capacity of 4.18 J/g^{0}C. 
A. 
B. 
C. 
D. 
E. 
5.  17. The rate constant of a firstorder decomposition reaction is 0.0147 s^{–1}. If the initial concentration of reactant is 0.178 M, what is the concentration of reactant after 30.0 seconds? 
A. 
B. 
C. 
D. 
E. 
6. 
22. For the firstorder reaction below, the initial concentration of A is 0.80 M. What is the halflife of the reaction if the concentration of A decreases to 0.10 M in 54 seconds?

A. 
B. 
C. 
D. 
E. 
7.  4. When 66.0 g of an unknown metal at 28.5^{0}C is placed in 83.0 g H_{2}O at 78.5^{0}C, the water temperature decreases to 75.9^{0}C. What is the specific heat capacity of the metal? The specific heat capacity of water is 4.184 J/g^{0}C. 
A. 
B. 
C. 
D. 
E. 
8.  The initial rates method was used to study the reaction below. A + 3B =2C [A] (mol/L) [B] (mol/L) D[A]/Dt (mol/L×s) 0.210 0.150 3.41 x 10^3 0.210 0.300 1.36 x 10^2 0.420 0.300 2.73 x 10^2 
A. 
B. 
C. 
D. 
E. 
9.  29. Which of the following may change the ratio of products to reactants in an equilibrium mixture for a chemical reaction involving gaseous species? 1. Increasing the temperature. 2. Adding a catalyst. 3. Adding gaseous reactants. 
A. 
B. 
C. 
D. 
E. 
10.  25. Write a balanced chemical equation which corresponds to the following equilibrium constant expression. 
A. 
B. 
C. 
D. 
E. 
11.  Which of the following statements is/are CORRECT? 1. Product concentrations appear in the numerator of an equilibrium constant expression. 2. A reaction favors the formation of products if K >> 1. 3. Stoichiometric coefficients are used as exponents in an equilibrium constant expression. 
A. 
B. 
C. 
D. 
E. 
12.  11. For the reaction below relate the rate of disappearance of hydrogen to the rate of formation of ammonia. N_{2}(g) + 3H_{2}(g) → 2NH_{3}(g) 
A. 
B. 
C. 
D. 
E. 
13. 
Use the equilibrium constants for the following reactions at 700 ^{0}C

A. 
B. 
C. 
D. 
E. 
14.  2. If 495 J is required to change the temperature of 12.7 g of sodium chloride from 75.0^{0}C to 135 ^{0}C, what is the specific heat of sodium chloride? 
A. 
B. 
C. 
D. 
E. 
15. 
Calcium carbonate decomposes to calcium oxide and carbon dioxide.

A. 
B. 
C. 
D. 
E. 
16.  3. Water has a specific heat of 4.18 J/g · ^{0}C. If 35.0 g of water at 98.8 ^{0}C loses 4.94 kJ of heat, what is the final temperature of the water? 
A. 
B. 
C. 
D. 
E. 
17. 
20. For the firstorder reaction below, the concentration of product B after 24.2 seconds is 0.322 M. If k = 8.75 × 10^{2} s^{1}, what was the initial concentration of A?

A. 
B. 
C. 
D. 
E. 
18.  1. If 50.0 g of benzene, C_{6}H_{6}, at 25.0^{0}C absorbs 2.71 kJ of energy in the form of heat, what is the final temperature of the benzene? The specific heat of benzene is 1.72 J/g·^{0}C. 
A. 
B. 
C. 
D. 
E. 
19.  5. A coffeecup calorimeter contains 10.0 g of water at 59.00^{0}C. If 3.00 g gold at 15.20 ^{0}C is placed in the calorimeter, what is the final temperature of the water in the calorimeter? The specific heat of water is 4.18 J/g ·^{0}C; the specific heat of gold is 0.128 J/g ·^{0}C. 
A. 
B. 
C. 
D. 
E. 
20.  12. The rate of reaction for the formation of carbon monoxide is measured at 1.24 mol/L·hr. What is the rate of formation of carbon monoxide in units of mol/L·s? CH_{3}CHO(g) → CH_{4}(g) + CO(g) 
A. 
B. 
C. 
D. 
E. 
21. 
21. For the secondorder reaction below, the rate constant of the reaction is 9.4 × 10^{–3} M^{–1}s^{–1}. How long (in seconds) is required to decrease the concentration of A from 2.16 M to 0.40 M?

A. 
B. 
C. 
D. 
E. 
22.  8. All of the following statements are true EXCEPT 
A. 
B. 
C. 
D. 
E. 
23.  28. For the system CO(g) + H_{2}O(g) CO_{2}(g) + H_{2}(g) K is 1.6 at 900 K. If 0.400 atm CO(g) and 0.400 atm H_{2}O(g) are combined in a sealed flask, what is the equilibrium partial pressure of CO_{2}(g)? 
A. 
B. 
C. 
D. 
E. 
24.  18. The rate constant for the decomposition of cyclobutane is 2.08 × 10^{2} s^{1} at high temperatures. C_{4}H_{8}(g) → 2C_{2}H_{4}(g) How many seconds are required for an initial concentration of 0.100 M C_{4}H_{8}(g) to decrease to 0.0450 M? 
A. 
B. 
C. 
D. 
E. 
25.  19. The reaction A → B follows firstorder kinetics with a halflife of 21.7 hours. If the concentration of A is 0.023 M after 48.0 hours, what is the initial concentration of A? 
A. 
B. 
C. 
D. 
E. 
26.  13. For the reaction below, if the rate of appearance of Br_{2} is 0.180 mol/L·s, what is the rate of disappearance of NOBr? 2NOBr(g) → 2NO(g) + Br_{2}(g) 
A. 
B. 
C. 
D. 
E. 
27. 
16. The initial rates method was used to study the reaction below.
2A + B + C → D + E

A. 
B. 
C. 
D. 
28.  . Nitrosyl chloride decomposes according to the chemical equation below. 2NOCl(g) 2NO(g) + Cl_{2}(g) A pressure of 0.320 atm of nitrosyl chloride is sealed in a flask and allowed to reach equilibrium. If 22.6% of the NOCl decomposes, what is the equilibrium constant for the reaction? 
A. 
B. 
C. 
D. 
E. 
29.  9. Determine the heat of reaction for the combustion of ammonia, 4NH_{3}(g) + 7O_{2}(g) → 4NO_{2}(g) + 6H_{2}O(l) using molar enthalpies of formation. NH3(g) –45.9 NO2(g) +33.1 H2O(l) –285.8 
A. 
B. 
C. 
D. 
E. 
30.  7. 10.0 g of ice at 0.00 ^{0}C is mixed with 25.0 g of water at 35.00^{0}C in a coffeecup calorimeter. What is the final temperature of the mixture? The specific heat of water is 4.18 J/g ^{0}C; the heat of fusion of water is 333 J/g. 
A. 
B. 
C. 
D. 
E. 